Explanation:
What if we could see back to the beginning of the universe?
We can -- since it takes the
age of the universe for light to cross the universe.
Peering at distant objects, therefore, tells us about
how the universe used to be, even
near its beginning.
Since telescopes are therefore also
time portals, observations of
distant clusters can be used, for example, to investigate when and how these
huge galaxy conglomerations formed.
Previously, the
redshiftrecord for a galaxy cluster was about 1.5, corresponding to about nine billion
light years distant.
Recently, using data including
X-ray images from the orbiting
Chandra X-Ray Observatory, a new farthest cluster was identified.
Shown above,
JKCS041 is seen at redshift 1.9, corresponding to nearly one billion light years farther than the previous record holder.
The hot X-ray gas that confirmed the
apparent galaxy grouping as a true cluster of galaxies is shown above in diffuse blue, superposed on an optical image showing many foreground stars.
JKCS041 is seen today as it appeared at only one quarter of the present age of the universe.